1. Field of Invention
The invention relates to a door lock and, in particular, to a door lock whose transmission mechanism is controlled by a key.
2. Related Art
FIG. 9 shows a conventional door lock. In its housing 90, a key retracts a lock tongue 91 and opens it. Also a knob drives another lock tongue 92 to retract and open. They connect the auxiliary lock ensembles 93 on both ends of the door. Therefore, to open the lock, one has to use a key and turn the knob. Such a door lock structure is more complicated and expensive. It is thus an objective of the invention to solve this problem.